In recent years, technologies related to machine communication (machine-to-machine communication), in which services are provided through autonomous communication between devices, have been under development. The European telecommunications standards institute (ETSI) defines three domains—namely, the application domain, the network domain, and the device domain—as a machine communication system reference model. Of these, in the device domain, application to lifeline control which covers electricity, gas and water, highway traffic systems (Intelligent Transport System (ITS)) and so on are already under study for practical use.
In the network domain, a cellular system that is based on the provisions of the 3GPP (3rd Generation Partnership Project) is a promising candidate to be employed. Consequently, with the 3GPP, activity to standardize machine communication, which is defined as “MTC (Machine Type Communication),” has started (non-patent literature 1).